The present invention relates to a balloon and particularly to an improved whistle balloon.
A toy balloon is commonly provided with a flange around the mouth through which the air being blown into. Thus, owing to the fact that the wall of the edge portion is thickened, it will not be vibrated by the expelled air as the inflated balloon being released. Consequently, the conventional whistle ballon is available only in the type that further mounted with a sound device therein to accomplish the desired sound-making function. The provision of this additional device will entail an extra cost of material and labour in manufacture.